Researchers using data from the James Webb Space Telescope recently announced they had detected biosignature gases on planet K2-18b. A new analysis of the same data casts doubt on the earlier findings

The James Webb Space Telescope may have detected life-associated gas in the atmosphere of a far-off planet. The news is being greeted with both enthusiasm and skepticism.

Earth, Mars and Venus all looked pretty similar when they first formed. Today, Mars is dry, cold, and dusty; Venus has a hot, crushing atmosphere. Why did these sibling planets turn out so different?

Scientists are thrilled with the tiny asphalt-black rocks, and most of the sample hasn't even been revealed yet.

Since touching down in Jezero Crater, NASA's Perseverance rover has already cached 6 samples that could one day be brought back to Earth. Astrobiologists hope they hold signs of past microbial life.